CN111727206B

CN111727206B - Polymerizable liquid crystal composition, optically anisotropic film, optical film, polarizing plate, and image display device

Info

Publication number: CN111727206B
Application number: CN201980013712.8A
Authority: CN
Inventors: 林大介; 松山拓史; 高桥庆太; 吉政庆介; 芥川畅之
Original assignee: Fujifilm Corp
Current assignee: Fujifilm Corp
Priority date: 2018-02-21
Filing date: 2019-02-21
Publication date: 2022-06-14
Anticipated expiration: 2039-02-21
Also published as: US20200369962A1; JPWO2019163878A1; WO2019163878A1; CN111727206A; KR20200105910A; US11702596B2; JP7022192B2; KR102424213B1

Abstract

The invention provides a polymerizable liquid crystal composition for forming an optically anisotropic film with excellent durability, an optically anisotropic film, an optical film, a polarizing plate and an image display device. The polymerizable liquid crystal composition of the present invention is a polymerizable liquid crystal composition comprising: the liquid crystal composition contains a polymerizable liquid crystal compound represented by the following formula (1) and an acidic compound, wherein the pKa of the acidic compound is more than-10 and 5 or less, and the content of the acidic compound is 20 parts by mass or less per 100 parts by mass of the polymerizable liquid crystal compound.

Description

Polymerizable liquid crystal composition, optically anisotropic film, optical film, polarizing plate, and image display device

Technical Field

The present invention relates to a polymerizable liquid crystal composition, an optically anisotropic film, an optical film, a polarizing plate, and an image display device.

Background

The polymerizable compound exhibiting reverse wavelength dispersibility has characteristics such as being capable of converting the wavelength of light accurately over a wide wavelength range and being capable of making a retardation film thin due to its high refractive index, and thus, studies have been actively made.

In addition, as a polymerizable compound exhibiting reverse wavelength dispersibility, it is generally required to use a T-type molecular design guideline, to shorten the wavelength of the major axis of the molecule and to lengthen the wavelength of the minor axis located at the center of the molecule.

Therefore, it is known that a cycloalkylene skeleton which does not absorb a wavelength is used for connecting a skeleton of a short axis located at the center of a molecule (hereinafter, also referred to as a "reverse wavelength dispersion-exhibiting portion") and a long axis of the molecule (for example, see patent documents 1 to 3).

Prior art documents

Patent document

Patent document 1: japanese patent laid-open No. 2010-031223

Patent document 2: international publication No. 2014/010325

Patent document 3: japanese patent laid-open publication No. 2016 081035

Disclosure of Invention

Technical problem to be solved by the invention

As a result of studies of patent documents 1 to 3, the present inventors have found that the following durability is a problem: depending on the type of polymerizable compound, the type of polymerization initiator, and the polymerization conditions such as the curing temperature, the birefringence may change when the optically anisotropic film formed is exposed to high temperature or high humidity.

Accordingly, an object of the present invention is to provide a polymerizable liquid crystal composition for forming an optically anisotropic film having excellent durability, an optically anisotropic film, an optical film, a polarizing plate, and an image display device.

Means for solving the technical problem

As a result of intensive studies to achieve the above object, the present inventors have found that: when an acidic compound satisfying a specific pKa value is used together with a polymerizable liquid crystal compound, the durability of the formed optically anisotropic film is good, and the present invention has been completed.

That is, it has been found that the above-mentioned problems can be achieved by the following configuration.

[1] A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound represented by the following formula (1) and an acidic compound,

the pKa of the acidic compound is more than-10 and less than 5,

the content of the acidic compound is 20 parts by mass or less per 100 parts by mass of the polymerizable liquid crystal compound.

[2] The polymerizable liquid crystal composition according to [1], wherein the value of pKa of the acidic compound and the value of the content of the acidic compound per 100 parts by mass of the polymerizable liquid crystal compound satisfy the following formula (I).

The value of content/(pKa value +10) is less than or equal to 0.01 and less than or equal to 1.5 … … (I)

[3] The polymerizable liquid crystal composition according to [1] or [2], wherein the molecular weight of the acidic compound is 120 or more.

[4] The polymerizable liquid crystal composition according to any one of [1] to [3], wherein the acidic compound is at least 1 compound selected from the group consisting of a phosphoric acid compound, a phosphonic acid compound and a sulfonic acid compound.

[5] The polymerizable liquid crystal composition according to any one of [1] to [4], wherein n in the formula (1) described later represents 2, and Ar in the formula (1) described later represents an aromatic ring selected from the group consisting of groups represented by the formulae (Ar-1) to (Ar-5) described later.

[6] An optically anisotropic film obtained by polymerizing the polymerizable liquid crystal composition described in any one of [1] to [5 ].

[7] The optically anisotropic film according to [6], wherein the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition is horizontally aligned after polymerization.

[8] An optical film having the optically anisotropic film of [6] or [7 ].

[9] A polarizing plate having the optical film according to [8] and a polarizer.

[10] An image display device having the optical film of [8] or the polarizing plate of [9 ].

Effects of the invention

According to the present invention, a polymerizable liquid crystal composition, an optically anisotropic film, an optical film, a polarizing plate, and an image display device for forming an optically anisotropic film having excellent durability can be provided.

Drawings

Fig. 1A is a schematic cross-sectional view showing an example of the optical film of the present invention.

Fig. 1B is a schematic cross-sectional view showing another example of the optical film of the present invention.

Fig. 1C is a schematic cross-sectional view showing another example of the optical film of the present invention.

Detailed Description

The present invention will be described in detail below.

The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.

In the present specification, the numerical range expressed by the term "to" refers to a range including numerical values before and after the term "to" as a lower limit value and an upper limit value.

In the present specification, the bonding direction of the divalent group (for example, -O-CO-) to be labeled is not particularly limited except when the bonding position is specified, and is, for example, D in the formula (Ar-3) described later¹is-CO-O-In the case of (2), if bonding to SP¹The position on the side is set to 1 and the position bonded to the carbon atom side is set to 2, then D¹May be 1-CO-O-2 or 1-O-CO-2.

[ polymerizable liquid Crystal composition ]

The polymerizable liquid crystal composition of the present invention is a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound represented by the following formula (1) (hereinafter, also simply referred to as "polymerizable liquid crystal compound (1)") and an acidic compound.

The pKa of the acidic compound is more than-10 and not more than 5.

The content of the acidic compound is 20 parts by mass or less based on 100 parts by mass of the polymerizable liquid crystal compound (1).

[ chemical formula 1]

In the present invention, as described above, by blending an acidic compound having a pKa of more than-10 and 5 or less (hereinafter, also simply referred to as "specific acidic compound") with the polymerizable liquid crystal compound (1), the durability of the formed optically anisotropic film is good.

Although details thereof are not clear, the present inventors presume as follows.

First, the present inventors speculate that the reason for the poor durability is because: the ester bond used for the connection of Ar and the molecular long axis in formula (1) is hydrolyzed under a high-temperature or high-humidity environment, whereby a part of the liquid crystal compound immobilized with a polymerizable group is released to have mobility, and the birefringence changes.

Thus, in the present invention, it is considered that: by blending a specific acidic compound, the basic component present in the composition system is neutralized and mixed, and as a result, the progress of hydrolysis promoted by the presence of the basic component is suppressed, and the durability is improved.

Hereinafter, each component of the polymerizable liquid crystal composition of the present invention will be described in detail.

[ polymerizable liquid Crystal Compound (1) ]

The polymerizable liquid crystal compound (1) contained in the polymerizable liquid crystal composition of the present invention is a polymerizable liquid crystal compound represented by the following formula (1).

[ chemical formula 2]

In the formula (1), Ar represents an n-valent aromatic group.

D represents a single bond, -COO-or-OCO-,

a represents an optionally substituted aromatic ring having 6 or more carbon atoms or an optionally substituted cycloalkane ring having 6 or more carbon atoms,

SP represents a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or-CH having 1 or more members constituting a linear or branched alkylene group having 1 to 12 carbon atoms₂A linking group having a valence of 2, substituted by-O-, -S-, -NH-, -N (Q) -or-CO-, Q represents a substituent,

l represents a polymerizable group, and L represents a polymerizable group,

m represents an integer of 0 to 2, n represents an integer of 1 or 2,

wherein D, A, SP and L, which are plural depending on the number of m or n, may be the same or different from each other.

In the formula (1), the aromatic group represented by Ar is a group containing an aromatic ring, and examples thereof include a group having a valence of n containing at least 1 aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring.

Here, as the aromatic hydrocarbon ring, for example, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthroline ring, and the like can be given.

Examples of the aromatic heterocyclic ring include a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring.

Among them, benzene ring, thiazole ring and benzothiazole ring are preferable.

In the formula (1), the aromatic ring having 6 or more carbon atoms represented by a includes, for example, aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring, phenanthroline ring, etc.; an aromatic heterocycle such as furan ring, pyrrole ring, thiophene ring, pyridine ring, thiazole ring, or benzothiazole ring. Among them, benzene rings (e.g., 1, 4-phenyl group, etc.) are preferred.

In the above formula (1), examples of the cycloalkane ring having 6 or more carbon atoms represented by a include cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclododecane ring, and the like, and among them, cyclohexane ring (e.g., cyclohexane-1, 4-diyl group, etc.) is preferable.

Examples of the substituent which may be contained in the aromatic ring having 6 or more carbon atoms or the cycloalkane ring having 6 or more carbon atoms include Y in the formula (Ar-1) described later¹The same substituents may be present.

In the formula (1), examples of the linear or branched alkylene group having 1 to 12 carbon atoms represented by SP include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a methylhexenyl group, and a heptenyl group. In addition, as described above, SP¹And SP²May be at least 1-CH constituting a linear or branched alkylene group having 1 to 12 carbon atoms₂A linking group having a valence of 2 which is substituted by-O-, -S-, -NH-, -N (Q) -or-CO-, and the substituent represented by Q is the same as Y in the formula (Ar-1) described later¹The same substituents may be present.

In the formula (1), the polymerizable group represented by L is not particularly limited, but is preferably a polymerizable group capable of radical polymerization or cationic polymerization.

As the radical polymerizable group, a well-known radical polymerizable group can be used, and as a preferred radical polymerizable group, an acryloyl group or a methacryloyl group can be mentioned. In this case, it is known that the polymerization rate of an acryloyl group is generally high, and an acryloyl group is preferable from the viewpoint of improving productivity, but a methacryloyl group can be similarly used as a polymerizable group.

As the cationically polymerizable group, a known cationically polymerizable group can be used, and specific examples thereof include alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spiroorthoester groups, and vinyloxy groups. Among them, an alicyclic ether group or an ethyleneoxy group is preferable, and an epoxy group, an oxetanyl group or an ethyleneoxy group is particularly preferable.

Examples of particularly preferable polymerizable groups include the following.

[ chemical formula 3]

In the formula (1), m represents an integer of 0 to 2, and is preferably 1 or 2, more preferably 1, from the viewpoint of exhibiting sufficient rigidity for exhibiting liquid crystallinity.

In the formula (1), n represents an integer of 1 or 2, and is preferably 2 because of easy synthesis and easy development of liquid crystal properties.

In the present invention, the polymerizable liquid crystal compound represented by the above formula (1) is preferably a compound exhibiting reverse wavelength dispersibility, because the polymerizable liquid crystal compound having reverse wavelength dispersibility tends to be significantly decomposed when used.

Here, the polymerizable liquid crystal compound of the "reverse wavelength dispersibility" means a compound in which, when the retardation (Re) value in a plane of a retardation film produced using the compound at a specific wavelength (visible light range) is measured, the Re value becomes equal or increases as the measurement wavelength increases.

Preferable examples of the compound exhibiting reverse wavelength dispersibility include compounds in which n in the formula (1) represents 2 and Ar in the formula (1) represents an aromatic ring selected from the group consisting of groups represented by the following formulae (Ar-1) to (Ar-5). In the following formulae (Ar-1) to (Ar-5), a represents a bonding position to an oxygen atom.

[ chemical formula 4]

In the above formula (Ar-1), Q¹Represents N or CH, Q²represents-S-, -O-or-N (R)¹)-，R¹Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Y¹Represents an optionally substituted aromatic hydrocarbon group having 6 to 12 carbon atoms or an aromatic heterocyclic group having 3 to 12 carbon atoms.

As R¹Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl.

As Y¹The aromatic hydrocarbon group having 6 to 12 carbon atoms includes, for example, an aryl group such as a phenyl group, a 2, 6-diethylphenyl group, or a naphthyl group.

As Y¹Examples of the aromatic heterocyclic group having 3 to 12 carbon atoms include heteroaryl groups such as thienyl, thiazolyl, furyl and pyridyl.

And as Y¹Examples of the substituent that may be contained include an alkyl group, an alkoxy group, and a halogen atom.

The alkyl group is preferably a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms (for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclohexyl group, etc.), further preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group or an ethyl group.

The alkoxy group is preferably an alkoxy group having 1 to 18 carbon atoms, more preferably an alkoxy group having 1 to 8 carbon atoms (e.g., methoxy group, ethoxy group, n-butoxy group, methoxyethoxy group), still more preferably an alkoxy group having 1 to 4 carbon atoms, and particularly preferably a methoxy group or an ethoxy group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and among them, a fluorine atom and a chlorine atom are preferable.

And, in the above formulae (Ar-1) to (Ar-5), Z¹、Z²And Z³Independently represent a hydrogen atom, a C1-valent aliphatic hydrocarbon group, a C3-20 1-valent alicyclic hydrocarbon group, a C6-20 1-valent aromatic hydrocarbon group, a halogen atom, a cyano group, a nitro group, -OR²、-NR³R⁴or-SR⁵，R²～R⁵Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Z¹And Z²May be bonded to each other to form an aromatic ring.

The 1-valent aliphatic hydrocarbon group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and specifically more preferably a methyl group, an ethyl group, an isopropyl group, a tert-amyl group (1, 1-dimethylpropyl group), a tert-butyl group, and a1, 1-dimethyl-3, 3-dimethyl-butyl group, and particularly preferably a methyl group, an ethyl group, and a tert-butyl group.

Examples of the 1-valent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, methylcyclohexyl, and ethylcyclohexyl; monocyclic unsaturated hydrocarbon groups such as cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclodecenyl, cyclopentadienyl, cyclohexadienyl, cyclooctadienyl and cyclodecadiene; bicyclo [2.2.1]Heptyl, bicyclo [2.2.2]Octyl, tricyclo [5.2.1.0^2,6]Decyl, tricyclo [3.3.1.1^3,7]Decyl, tetracyclic [6.2.1.1^3,6.0^2,7]And polycyclic saturated hydrocarbon groups such as dodecyl and adamantyl.

Specific examples of the 1-valent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a 2, 6-diethylphenyl group, a naphthyl group, and a biphenyl group, with an aryl group having 6 to 12 carbon atoms (particularly, a phenyl group) being preferred.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and among them, a fluorine atom, a chlorine atom and a bromine atom are preferable.

On the other hand, as R⁶～R⁹Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl and n-butylIsobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, and the like.

And, in the above formulae (Ar-2) and (Ar-3), A¹And A²Each independently represents a group selected from the group consisting of-O-, -N (R)⁶) A radical of the group consisting of-S-and-CO-, R⁶Represents a hydrogen atom or a substituent.

As R⁶Examples of the substituent include Y in the formula (Ar-1)¹The same substituents as those that may be present.

In the formula (Ar-2), X represents a group 14 to 16 non-metal atom to which a hydrogen atom or a substituent may be bonded.

Examples of the group 14 to 16 non-metal atom represented by X include an oxygen atom, a sulfur atom, a substituted nitrogen atom, and a substituted carbon atom, and specific examples of the substituent include an alkyl group, an alkoxy group, an alkyl-substituted alkoxy group, a cyclic alkyl group, an aryl group (e.g., phenyl group, naphthyl group, etc.), a cyano group, an amino group, a nitro group, an alkylcarbonyl group, a sulfo group, and a hydroxyl group.

And, in the above formula (Ar-3), D¹And D²Each independently represents a single bond or-CO-, -O-, -S-, -C (-S) -, -CR⁷R⁸-、-CR⁹＝CR¹⁰-、-NR¹¹-or a linking group having a valence of 2 comprising a combination of 2 or more of them, R⁷～R¹¹Each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms.

Here, as D¹And D²Examples of the 2-valent linking group include-CO-O-, -C (═ S) O-, -CR⁷R⁸-、-CR⁷R⁸-CR⁷R⁸-、-O-CR⁷R⁸-、-CR⁷R⁸-O-CR⁷R⁸-、-CO-O-CR⁷R⁸-、-O-CO-CR⁷R⁸-、-CR⁷R⁸-O-CO-CR⁷R⁸-、-CR⁷R⁸-CO-O-CR⁷R⁸-、-NR¹¹-CR⁷R⁸-and-CO-NR¹¹-and the like. Among them, preferred is-CO-O-.

And, in the above formula (Ar-3), SP¹And SP²Each independently represents a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or at least 1-CH constituting a linear or branched alkylene group having 1 to 12 carbon atoms₂A linking group having a valence of 2, which is substituted by-O-, -S-, -NH-, -N (Q) -or-CO-, wherein Q represents a substituent. Examples of the substituent include Y in the above formula (Ar-1)¹The same substituents as those that may be present.

Here, the linking group having a valence of 2 includes the same groups as those described for SP in the above formula (1).

And, in the above formula (Ar-3), L¹And L²Each independently represents a 1-valent organic group.

Examples of the 1-valent organic group include an alkyl group, an aryl group, and a heteroaryl group. The alkyl group may be linear, branched or cyclic, but is preferably linear. The number of carbon atoms of the alkyl group is preferably 1 to 30, more preferably 1 to 20, and still more preferably 1 to 10. Also, the aryl group may be monocyclic or polycyclic, but monocyclic is preferable. The number of carbon atoms of the aryl group is preferably 6 to 25, more preferably 6 to 10. Also, the heteroaryl group may be monocyclic or polycyclic. The number of hetero atoms constituting the heteroaryl group is preferably 1 to 3. The hetero atom constituting the heteroaryl group is preferably a nitrogen atom, a sulfur atom, or an oxygen atom. The number of carbon atoms of the heteroaryl group is preferably 6 to 18, more preferably 6 to 12. The alkyl group, the aryl group and the heteroaryl group may be unsubstituted or may have a substituent. Examples of the substituent include Y in the above formula (Ar-1)¹The same substituents as those that may be present.

In the formulae (Ar-4) to (Ar-5), Ax represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring.

In the formulae (Ar-4) to (Ar-5), Ay represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, or an organic group having 2 to 30 carbon atoms which has at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring.

Here, the aromatic ring in Ax and Ay may have a substituent, or Ax and Ay may be bonded to form a ring.

And, Q³Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.

Ax and Ay are groups described in paragraphs [0039] to [0095] of patent document 2 (International publication No. 2014/010325).

And as Q³Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl and n-hexyl groups, and examples of the substituent include the same as Y in the formula (Ar-1)¹The same substituents as those that may be present.

Specific examples of the polymerizable liquid crystal compound (1) represented by the above formula (1) include a compound represented by the general formula (I) described in japanese patent application laid-open No. 2008-297210 (particularly, compounds described in paragraphs [0034] to [0039 ]), a compound represented by the general formula (1) described in japanese patent application laid-open No. 2010-084032 (particularly, compounds described in paragraphs [0067] to [0073 ]), a compound represented by the general formula (II) described in japanese patent application laid-open No. 2016-053709 (particularly, compounds described in paragraphs [0036] to [0043 ]), and a compound represented by the general formula (1) described in japanese patent application laid-open No. 2016-open No. 081 (particularly, compounds described in paragraphs [0043] to [0055 ]), and the like.

Further, from the reason that the reverse wavelength dispersibility is improved, the polymerizable liquid crystal compound (1) represented by the formula (1) may be a polymerizable liquid crystal compound in which D in the formula (1) is a single bond and a in the formula (1) represents a cycloalkane ring having 6 or more carbon atoms.

As such polymerizable liquid crystal compounds, for example, compounds represented by the following formulas (1) to (10) are preferably cited, and specifically, compounds having side chain structures shown in the following tables 1 and 2 as K (side chain structure) in the following formulas (1) to (10) are cited, respectively.

In tables 1 and 2, each "+" indicated in the side chain structure of K indicates a bonding position to an aromatic ring.

In the following description, a compound represented by the following formula (1) and having a group represented by 1-1 in table 1 is referred to as "compound (1-1-1)", and compounds having other structural formulae and groups are referred to by the same method. For example, a compound represented by the following formula (2) and having a group represented by 2-3 in the following table 2 can be labeled as "compound (2-2-3)".

In the side chain structures represented by 1-2 in table 1 and 2-2 in table 2, the groups adjacent to the acryloyloxy group and the methacryloyl group respectively represent propylene groups (groups obtained by substituting ethylene with methyl groups), and represent a mixture of positional isomers in which the methyl groups are different in position.

[ chemical formula 5]

[ Table 1]

[ Table 2]

[ specific acidic Compound ]

The specific acidic compound contained in the polymerizable liquid crystal composition of the present invention is an acidic compound having a pKa of more than-10 and 5 or less.

Here, the pKa refers to an acid dissociation constant, and the lower the value, the higher the acid strength.

In the present specification, pKa is calculated according to the following steps (i) to (v). That is, when the pKa of the specific acidic compound can be calculated in (i), the pKa calculated in (i) is set to the pKa of the specific acidic compound. If the pKa cannot be calculated by (i), an attempt is made to calculate the pKa by (ii), and if the pKa can be calculated by (ii), the value is set to the pKa of the specific acidic compound. If the pKa cannot be calculated in (ii), then the pKa is calculated in (iii), and if the pKa can be calculated in (iii), the value is assumed to be the pKa of the specific acidic compound. If the pKa cannot be calculated by (iii), then an attempt is made to calculate the pKa by (iv), and the value that enables the calculation of the pKa in (iv) is taken as the pKa of the specific acidic compound. If the pKa cannot be calculated by (iv), then an attempt is made to calculate the pKa by (v), and the value at which the pKa can be calculated by (v) is taken as the pKa of the specific acidic compound.

(i) The pKa values of the database based on the hammett substituent constants and the known literature values were calculated using the following software package 1.

< software Package 1 >

Marvin Sketch 18.3(ChemAxon)

The pKa of the compound that can be calculated using the above software package 1 was used by rounding off the second decimal place.

(ii) Compounds that could not be calculated using software package 1 were solved using software package 2.

< software Package 2 >

Advanced Chemistry Development(ACD/Labs)Software V8.14 for Solaris(1994-2007ACD/Labs)。

The pKa of the compound that can be calculated using the above software package 2 was used by rounding off the second decimal place.

(iii) Superacids that cannot be calculated using the software package 2 (superatomic compounds containing a boron atom, a phosphorus atom, or the like that cannot be calculated due to procedural problems) are cited as pka (dce) described in table 1 of document 1(j. Here, DCM means the pKa of 1, 2-dichloroethane as a solvent.

(iv) Further, as for the super Acid which is not described in the above document 1, the "Fluoride ion affinity of Lewis Acid (kJ/mol)" described in table 3 of reference 2 (angle. chem. int. ed.,2004,43, 2066) was calculated using a conversion factor.

Namely, the "HBF" described in both of documents 1 and 2 is used₄"pKa is calculated by multiplying a conversion coefficient (-10.3/338) calculated from the ratio of the Lewis acid fluoride ion affinity (338) by the value of the Lewis acid fluoride ion affinity of each component described in document 2. For example, due to [ PF ] in Table 3 of document 2₆]^-Has a fluoride ion affinity of 394, thus HPF₆The pKa of (a) can be calculated to be 394 × (-10.3/338) — 12.0.

(v) The superacids that cannot be calculated in the above (i) to (iv) and the compounds not described in the above documents 1 and 2 are defined as values equivalent to those of the compounds having similar structures in the present invention.

In the present invention, the pKa of the specific acidic compound is preferably-5 to 5, more preferably-2 to 3, from the viewpoint of further improving the durability.

In the present invention, the molecular weight of the specific acidic compound is preferably 120 or more, more preferably 120 or more and 500 or less, and further preferably 150 or more and 350 or less, from the viewpoint that the compound is less likely to volatilize when the optically anisotropic film is formed and the durability is further improved.

Specific examples of such specific acidic compounds include those shown in table 3 below.

[ Table 3]

In the present invention, the specific acidic compound is preferably at least 1 compound selected from the group consisting of phosphoric acid compounds, phosphonic acid compounds, and sulfonic acid compounds, and more preferably a phosphonic acid compound or a sulfonic acid compound, from the viewpoint of further improving durability.

In the present invention, the content of the specific acidic compound is 20 parts by mass or less, preferably 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and still more preferably 0.2 to 5 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound (1).

In the case where the polymerizable liquid crystal composition of the present invention contains another polymerizable compound described later, the content of the specific acidic compound is a content (part by mass) based on 100 parts by mass of the total of the polymerizable liquid crystal compound (1) and the other polymerizable compound.

In particular, from the viewpoint of further improving the durability, the value of the pKa of the specific acidic compound and the value of the content (parts by mass) of the specific acidic compound with respect to 100 parts by mass of the polymerizable liquid crystal compound (1) preferably satisfy the following formula (I), more preferably satisfy the following formula (Ia), still more preferably satisfy the following formula (Ib), and particularly preferably satisfy the following formula (Ic).

The value of content/(pKa value +10) is not less than 0.03 and not more than 1.0 … … (Ia)

The value of content/(pKa value +10) is less than or equal to 0.05 and less than or equal to 0.8 … … (Ib)

The value of content/(pKa value +10) is less than or equal to 0.10 and less than or equal to 0.6 … … (Ic)

[ other polymerizable Compound ]

The polymerizable liquid crystal composition of the present invention may contain another polymerizable compound having 1 or more polymerizable groups in addition to the polymerizable liquid crystal compound (I) and the polymerizable compound (II).

The polymerizable group of the other polymerizable compound is not particularly limited, and examples thereof include an acryloyl group, a methacryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, acryl and methacryl are preferable.

The other polymerizable compound is preferably another polymerizable compound having 1 to 4 polymerizable groups, and more preferably another polymerizable compound having 2 polymerizable groups, because the moist heat resistance of the formed optical anisotropic film is further improved.

Examples of the other polymerizable compounds include those described in paragraphs [0073] to [0074] of Japanese patent laid-open publication No. 2016-053709.

Further, examples of the other polymerizable compounds include compounds represented by the formulae (M1), (M2) and (M3) described in paragraphs [0030] to [0033] of Japanese patent application laid-open No. 2014-077068, and more specifically, specific examples described in paragraphs [0046] to [0055] of Japanese patent application laid-open No. 2014-077068.

Further, as the other polymerizable compound, polymerizable compounds having the structures of the formulae (1) to (3) described in Japanese patent application laid-open No. 2014-198814 can be preferably used, and more specifically, specific examples described in paragraphs [0020] to [0035], [0042] to [0050] and [0056] to [0057] of Japanese patent application laid-open No. 2014-198814 can be mentioned.

The content of such other polymerizable compound in the case of containing it is preferably less than 50% by mass, more preferably 40% by mass or less, and still more preferably 2 to 30% by mass, based on the total mass including the polymerizable liquid crystal compound (I) and the polymerizable compound (II).

[ polymerization initiator ]

The polymerizable liquid crystal composition of the present invention preferably contains a polymerization initiator.

The polymerization initiator to be used is preferably a photopolymerization initiator capable of initiating a polymerization reaction by Ultraviolet (UV) irradiation.

Examples of the photopolymerization initiator include an α -carbonyl compound (described in U.S. Pat. Nos. 2367661 and 2367670), an acyloin ether (described in U.S. Pat. No. 2448828), an α -hydrocarbon-substituted aromatic acyloin compound (described in U.S. Pat. No. 2722512), a polyquinone compound (described in U.S. Pat. No. 3046127 and U.S. Pat. No. 2951758), a combination of a triarylimidazole dimer and p-aminophenyl ketone (described in U.S. Pat. No. 3549367), an acridine and phenazine compound (described in Japanese patent publication No. 60-105667 and U.S. Pat. No. 4239850), an oxadiazole compound (described in U.S. Pat. No. 4212970), an acylphosphine oxide compound (described in Japanese patent publication No. 63-040799, Japanese patent publication No. 5-029234, a-3526, an acylphosphine oxide compound, Japanese patent laid-open Nos. H10-095788 and H10-029997).

In the present invention, the polymerization initiator is also preferably an oxime type polymerization initiator, and specific examples thereof include the initiators described in paragraphs [0049] to [0052] of International publication No. 2017/170443.

[ solvent ]

The polymerizable liquid crystal composition of the present invention preferably contains a solvent from the viewpoint of workability for forming an optically anisotropic film and the like.

Specific examples of the solvent include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, etc.), ethers (e.g., dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., toluene, xylene, trimethylbenzene, etc.), halogenated carbons (e.g., dichloromethane, dichloroethane, dichlorobenzene, chlorotoluene, etc.), esters (e.g., methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, etc.), one of them may be used alone or 2 or more may be used simultaneously.

[ leveling agent ]

The polymerizable liquid crystal composition of the present invention preferably contains a leveling agent from the viewpoint of keeping the surface of the optically anisotropic film smooth and facilitating alignment control.

As such a leveling agent, a fluorine-based leveling agent or a silicon-based leveling agent is preferable because the leveling effect is high with respect to the amount added, and a fluorine-based leveling agent is more preferable because bleeding (blooming, bleeding) is less likely to occur.

As the leveling agent, specifically, examples thereof include compounds described in paragraphs [0079] to [0102] of Japanese patent laid-open No. 2007-069471, compounds described in paragraphs [0020] to [0032] of Japanese patent laid-open No. 2013-047204, compounds described in general formula (I) of Japanese patent laid-open No. 2012-211306 (particularly, compounds described in paragraphs [0022] to [0029 ]), liquid crystal alignment improvers described in Japanese patent laid-open No. 2002-129162 (particularly, compounds described in paragraphs [0076] to [0078] and [0082] to [0084 ]), and compounds described in paragraphs [ I), (II) and (III) of general formula (I), (II) and (III) of Japanese patent laid-open No. 2005-099248 (particularly, compounds described in paragraphs [0092] 0096), and the like. Further, the functional group may also function as an alignment control agent described later.

[ orientation controlling agent ]

The polymerizable liquid crystal composition of the present invention may contain an alignment controlling agent, if necessary.

The orientation control agent can form various orientation states such as homeotropic orientation (Vertical orientation), tilt orientation, hybrid orientation, and cholesteric orientation in addition to uniform orientation, and can control and realize a specific orientation state more uniformly and more precisely.

As the orientation control agent for promoting uniform orientation, for example, a low molecular orientation control agent or a high molecular orientation control agent can be used.

As the low-molecular orientation controlling agent, for example, the descriptions of paragraphs [0009] to [0083] of Japanese patent laid-open publication No. 2002-020363, paragraphs [0111] to [0120] of Japanese patent laid-open publication No. 2006-106662, and paragraphs [0021] to [0029] of Japanese patent laid-open publication No. 2012-211306 can be referred to, and the contents thereof are incorporated in the present specification.

Further, as the orientation controlling agent for the polymer, for example, paragraphs [0021] to [0057] of Japanese patent laid-open No. 2004-198511 and paragraphs [0121] to [0167] of Japanese patent laid-open No. 2006-106662 are referred to and are incorporated herein by reference.

Examples of the orientation controlling agent for forming or promoting vertical orientation include a boric acid compound and an onium salt compound, and specifically, compounds described in paragraphs [0023] to [0032] of Japanese patent laid-open No. 2008-225281, paragraphs [0052] to [0058] of Japanese patent laid-open No. 2012-208397, paragraphs [0024] to [0055] of Japanese patent laid-open No. 2008-026730, and paragraphs [0043] to [0055] of Japanese patent laid-open No. 2016-193869 can be cited, and the contents thereof are incorporated in the present specification.

On the other hand, the cholesteric alignment can be achieved by adding a chiral agent to the polymerizable composition of the present invention, and the direction of cyclotron of cholesteric alignment can be controlled according to the direction of chirality. In addition, the pitch of the cholesteric alignment can be controlled according to the alignment restriction force of the chiral agent.

The content of the orientation-controlling agent in the case of containing the orientation-controlling agent is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, based on the total solid content in the polymerizable liquid crystal composition. When the content is within this range, an optically anisotropic film which realizes a desired alignment state, is free from precipitation, phase separation, alignment defects, and the like, and is uniform and has high transparency can be obtained.

These alignment control agents can also impart a polymerizable functional group, particularly a polymerizable functional group capable of polymerizing with the polymerizable liquid crystal compound constituting the polymerizable liquid crystal composition of the present invention.

[ other achievements ]

The polymerizable liquid crystal composition of the present invention may further contain components other than the above-mentioned components, and examples thereof include liquid crystal compounds other than the above-mentioned polymerizable liquid crystal compounds, surfactants, tilt angle control agents, alignment aids, plasticizers, and crosslinking agents.

[ optically Anisotropic film ]

The optically anisotropic film of the present invention is obtained by polymerizing the polymerizable liquid crystal composition of the present invention.

Examples of the method for forming the optically anisotropic film include a method in which the polymerizable liquid crystal composition of the present invention is used to set a desired alignment state, and then the composition is fixed by polymerization.

The polymerization conditions are not particularly limited, but in polymerization by light irradiation, ultraviolet rays are preferably used. The irradiation dose is preferably 10mJ/cm²～50J/cm²More preferably 20mJ/cm²～5J/cm²More preferably 30mJ/cm²～3J/cm²Particularly preferably 50 to 1000mJ/cm². Further, the polymerization reaction may be carried out under heating to promote the polymerization reaction.

In the present invention, the optically anisotropic film may be formed on an arbitrary support in the optical film of the present invention described later, or on a polarizer in the polarizing plate of the present invention described later.

In the present invention, it is preferable that the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition of the present invention is immobilized in a state of being horizontally aligned after polymerization, from the viewpoint of causing the formed optically anisotropic film to function as a positive a plate.

Here, the positive a plate (positive a plate) is defined in the following manner.

When the refractive index in the slow axis direction (direction in which the in-plane refractive index is the largest) in the film plane is nx, the refractive index in the direction orthogonal to the slow axis in the plane is ny, and the refractive index in the thickness direction is nz, the positive a plate satisfies the relationship of the following expression (a 1). In addition, Rth of the positive a plate shows a positive value.

Formula (A1) nx > ny ≈ nz

The term "substantially" as used herein includes not only the case where both are completely identical but also the case where both are substantially identical. The term "substantially the same" is included in "ny ≈ nz" even if (ny-nz) × d (where d is the thickness of the thin film) is-10 to 10nm, preferably-5 to 5nm, and is included in "nx ≈ nz" even if (nx-nz) × d is-10 to 10nm, preferably-5 to 5nm, for example.

The optically anisotropic film of the present invention preferably satisfies the following formula (II).

0.50＜Re(450)/Re(550)＜1.00……(II)

In the formula (II), Re (450) represents the in-plane retardation of the optically anisotropic film at a wavelength of 450nm, and Re (550) represents the in-plane retardation of the optically anisotropic film at a wavelength of 550 nm. In the present specification, when the measurement wavelength of retardation is not specified, the measurement wavelength is 550 nm.

The values of the in-plane retardation and the retardation in the thickness direction are values measured using an AxoScan OPMF-1 (manufactured by OptoScience, inc.) and using light of a measurement wavelength.

Specifically, the average refractive index ((Nx + Ny + Nz)/3) and the film thickness (d (μm)) were input by using the AxoScan OPMF-1 to calculate as follows:

slow axis direction (°)

Re(λ)＝R0(λ)

Rth(λ)＝((nx+ny)/2-nz)×d。

R0 (. lamda.) is a numerical value calculated by Axoscan OPMF-1, but refers to Re (. lamda.).

[ optical film ]

The optical film of the present invention is an optical film having the optically anisotropic film of the present invention.

Fig. 1A, 1B, and 1C (hereinafter, simply referred to as "fig. 1" without particularly distinguishing between these figures) are schematic cross-sectional views each showing an example of the optical film of the present invention.

Fig. 1 is a schematic view, and the relationship of the thicknesses, positional relationship, and the like of the respective layers do not necessarily coincide with reality, and the support, alignment film, and hard coat layer shown in fig. 1 are all arbitrary constituent members.

The optical film 10 shown in fig. 1 has a support 16, an alignment film 14, and an optically anisotropic film 12 in this order.

Also, as shown in fig. 1B, the optical film 10 may have a hard coat layer 18 on the side of the support 16 opposite to the side on which the alignment film 14 is provided, and as shown in fig. 1C, may have a hard coat layer 18 on the side of the optically anisotropic film 12 opposite to the side on which the alignment film 14 is provided.

Hereinafter, various members used in the optical film of the present invention will be described in detail.

[ optically anisotropic film ]

The optical anisotropic film of the present invention has the above-described optical anisotropic film of the present invention.

In the optical film of the present invention, the thickness of the optically anisotropic film is not particularly limited, but is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

[ support body ]

As described above, the optical film of the present invention may have a support as a substrate for forming an optically anisotropic film.

Such a support is preferably transparent, and specifically, the light transmittance is preferably 80% or more.

Examples of such a support include a glass substrate and a polymer film, and examples of a material of the polymer film include a cellulose-based polymer; acrylic polymers having an acrylate polymer such as polymethyl methacrylate and polymers containing a lactone ring; a thermoplastic norbornene-based polymer; a polycarbonate-series polymer; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such AS polystyrene and acrylonitrile-styrene copolymer (AS resin); polyolefin polymers such as polyethylene, polypropylene, and ethylene-propylene copolymers; a vinyl chloride polymer; amide polymers such as nylon and aromatic polyamide; an imide polymer; a sulfone-based polymer; a polyether sulfone-based polymer; a polyether ether ketone polymer; polyphenylene sulfide-based polymer; a vinylidene chloride polymer; a vinyl alcohol polymer; a vinyl butyral polymer; an aryl ester polymer; a polyoxymethylene-based polymer; an epoxy polymer; or a polymer obtained by mixing these polymers.

Further, a polarizer described later may also serve as the support.

In the present invention, the thickness of the support is not particularly limited, but is preferably 5 to 60 μm, and more preferably 5 to 30 μm.

[ alignment film ]

When the optical film of the present invention has any of the above-mentioned supports, it is preferable to have an alignment film between the support and the optically anisotropic film. In addition, the above-described embodiment may be adopted in which the support also serves as an alignment film.

The alignment film generally has a polymer as a main component. As a polymer material for an alignment film, there are many documents describing that a plurality of commercial products can be obtained.

The polymer material utilized in the present invention is preferably polyvinyl alcohol or polyimide and derivatives thereof. Especially preferred are modified and unmodified polyvinyl alcohols.

Examples of the alignment film that can be used in the present invention include the alignment films described in international publication No. 01/088574, page 43, line 24 to page 49, line 8; modified polyvinyl alcohols described in paragraphs [0071] to [0095] of Japanese patent No. 3907735; a liquid crystal alignment film formed by a liquid crystal alignment agent as described in Japanese patent laid-open publication No. 2012-155308.

In the present invention, it is also preferable to use a photo-alignment film as the alignment film, because the photo-alignment film does not contact the surface of the alignment film when the alignment film is formed, and thus deterioration of the surface morphology can be prevented.

The photo-alignment film is not particularly limited, and a polymer material such as a polyamide compound or a polyimide compound described in paragraphs [0024] to [0043] of international publication No. 2005/096041; a liquid crystal alignment film formed by a liquid crystal alignment agent having a photo-alignment group as described in Japanese patent laid-open No. 2012-155308; the trade name is LPP-JP265CP manufactured by the company of Rolic Technologies, etc.

In the present invention, the thickness of the alignment film is not particularly limited, but is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm, and even more preferably 0.01 to 0.5 μm, from the viewpoint of reducing surface irregularities that can be present on the support and forming an optically anisotropic film having a uniform film thickness.

[ hard coating ]

In order to impart physical strength to the film, it is preferable that the optical film of the present invention has a hard coat layer. Specifically, the support may have a hard coat layer on the side opposite to the side on which the alignment film is provided (see fig. 1B), or may have a hard coat layer on the side opposite to the side on which the alignment film is provided (see fig. 1C).

As the hard coat layer, the hard coat layers described in paragraphs [0190] to [0196] of Japanese patent laid-open No. 2009 and 098658 can be used.

[ other optically anisotropic films ]

The optical film of the present invention may further have other optically anisotropic films different from the optically anisotropic film of the present invention.

That is, the optical film of the present invention may have a laminated structure of the optical anisotropic film of the present invention and other optical anisotropic films.

The other optical anisotropic film is not particularly limited as long as it is an optical anisotropic film obtained by using the other polymerizable compound (particularly, liquid crystal compound) without blending any of the polymerizable liquid crystal compound (I) and the polymerizable compound (II).

Here, generally, liquid crystal compounds can be classified into rod-like types and disk-like types according to their shapes. Moreover, they are of the low-molecular and high-molecular type, respectively. The polymer generally refers to a polymer having a polymerization degree of 100 or more (polymer physical/phase transition kinetics, Tujing, 2 nd page, Shibo bookshop, 1992). In the present invention, any liquid crystal compound can also be used, but a rod-like liquid crystal compound or a discotic liquid crystal compound (discotic liquid crystal compound) is preferably used. It is also possible to use 2 or more kinds of rod-like liquid crystal compounds, 2 or more kinds of discotic liquid crystal compounds, or a mixture of rod-like liquid crystal compounds and discotic liquid crystal compounds. For the immobilization of the liquid crystal compound, it is more preferable to use a rod-shaped liquid crystal compound or a disk-shaped liquid crystal compound having a polymerizable group, and it is further preferable that the liquid crystal compound has 2 or more polymerizable groups in1 molecule. When the liquid crystal compound is a mixture of 2 or more species, it is preferable that at least 1 liquid crystal compound has 2 or more polymerizable groups in1 molecule.

As the rod-like liquid crystal compound, for example, the compounds described in scheme 1 of Japanese patent application laid-open No. 11-513019 or paragraphs [0026] to [0098] of Japanese patent application laid-open No. 2005-289980 can be preferably used, and as the disk-like liquid crystal compound, for example, the compounds described in paragraphs [0020] to [0067] of Japanese patent application laid-open No. 2007-laid-open No. 108732 or paragraphs [0013] to [0108] of Japanese patent application laid-open No. 2010-laid-open No. 244038 can be preferably used, but not limited thereto.

[ ultraviolet light absorber ]

The optical film of the present invention preferably includes an Ultraviolet (UV) absorber in consideration of the influence of external light, particularly, ultraviolet rays.

The ultraviolet absorber may be contained in the optically anisotropic film of the present invention, or may be contained in a member other than the optically anisotropic film constituting the optical film of the present invention. As the member other than the optically anisotropic film, for example, a support is preferably used.

As the ultraviolet absorber, any conventionally known ultraviolet absorber that can exhibit ultraviolet absorbability can be used. Among such ultraviolet absorbers, benzotriazole-based or hydroxyphenyltriazine-based ultraviolet absorbers are preferably used from the viewpoint of obtaining ultraviolet absorbability (ultraviolet cutting ability) which is high and is used in image display devices.

In addition, in order to widen the absorption width of ultraviolet rays, 2 or more kinds of ultraviolet absorbers having different maximum absorption wavelengths can be used simultaneously.

Specific examples of the ultraviolet absorber include compounds described in paragraphs [0258] to [0259] of Japanese patent laid-open publication No. 2012-018395, compounds described in paragraphs [0055] to [0105] of Japanese patent laid-open publication No. 2007-072163, and the like.

Examples of commercially available products include Tinuvin400, Tinuvin405, Tinuvin460, Tinuvin477, Tinuvin479, and Tinuvin1577 (both manufactured by BASF corporation).

[ polarizing plate ]

The polarizing plate of the present invention has the optical film of the present invention and a polarizer described above.

[ polarizer ]

The polarizer included in the polarizing plate of the present invention is not particularly limited as long as it has a function of converting light into specific linearly polarized light, and conventionally known absorption polarizers and reflection polarizers can be used.

As the absorption type polarizer, an iodine type polarizer, a dye type polarizer using a dichroic dye, a polyene type polarizer, and the like can be used. The iodine-based polarizer and the dye-based polarizer can be used as both a coated polarizer and a stretched polarizer, but a polarizer produced by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and stretching the adsorbed iodine or dichroic dye is preferable.

Further, as a method for obtaining a polarizer by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate, there can be mentioned japanese patent No. 5048120, japanese patent No. 5143918, japanese patent No. 4691205, japanese patent No. 4751481, and japanese patent No. 4751486, and known techniques related to these polarizers can be preferably used.

As the reflective polarizer, a polarizer obtained by laminating thin films having different birefringence, a wire grid polarizer, a polarizer obtained by combining a cholesteric liquid crystal having a selective reflection region and an 1/4 wavelength plate, and the like can be used.

Among them, from the viewpoint of more excellent adhesion, it is preferable to contain a polyvinyl alcohol resin (containing-CH)₂-CHOH-as a polymer of repeating units. In particular, at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymer).

In the present invention, the thickness of the polarizer is not particularly limited, but is preferably 3 μm to 60 μm, more preferably 5 μm to 30 μm, and still more preferably 5 μm to 15 μm.

[ adhesive layer ]

The polarizing plate of the present invention may have an adhesive layer disposed between the optically anisotropic film and the polarizer in the optical film of the present invention.

The pressure-sensitive adhesive layer used for laminating an optically anisotropic film and a polarizer includes, for example, a material having a ratio (tan δ ═ G "/G ') of storage modulus G' to loss elastic modulus G ″ measured by a dynamic viscoelasticity measuring apparatus of 0.001 to 1.5, and includes a so-called pressure-sensitive adhesive, a material that is easily subject to creep, and the like. Examples of the binder that can be used in the present invention include, but are not limited to, a polyvinyl alcohol-based binder.

[ image display apparatus ]

The image display device of the present invention is an image display device having the optical film of the present invention or the polarizing plate of the present invention.

The display element used in the image display device of the present invention is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter, abbreviated as "EL") display panel, and a plasma display panel.

Among them, a liquid crystal cell and an organic EL display panel are preferable, and a liquid crystal cell is more preferable. That is, as the image display device of the present invention, a liquid crystal display device using a liquid crystal cell as a display element and an organic EL display device using an organic EL display panel as a display element are preferable, and a liquid crystal display device is more preferable.

[ liquid Crystal display device ]

A liquid crystal display device as an example of the image display device of the present invention is a liquid crystal display device having the polarizing plate and the liquid crystal cell of the present invention described above.

In the present invention, among the polarizing plates provided on both sides of the liquid crystal cell, the polarizing plate of the present invention is preferably used as the front polarizing plate, and more preferably used as the front and rear polarizing plates.

Hereinafter, a liquid crystal cell constituting the liquid crystal display device will be described in detail.

< liquid crystal cell >

The liquid crystal cell used In the liquid crystal display device is preferably a VA (Vertical Alignment) mode, an OCB (Optically Compensated Bend) mode, an IPS (In-Plane-Switching) mode, or a TN (Twisted Nematic) mode, but is not limited thereto.

In a TN mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially horizontally when no voltage is applied, and further twisted to 60 to 120 degrees. TN mode liquid crystal cells are most commonly used as color TFT liquid crystal display devices and are described in various documents.

In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied. The VA mode liquid crystal cell includes (1) a narrow VA mode liquid crystal cell (described in japanese patent application laid-open No. 2-176625) in which rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied and are aligned substantially horizontally when a voltage is applied, and further includes (2) a liquid crystal cell (SID97, described in Digest of tech. papers 28 (1997)) 845) in which the VA mode is multi-domain (MVA mode) in order to enlarge a viewing angle, (3) a liquid crystal cell (n-ASM mode) in which the rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied and are twisted in multi-domain alignment when a voltage is applied (described in proceedings 58 to 59 (1998)) of japan liquid crystal association), and (4) a liquid crystal cell (LCD International 98) in a surveyal mode. Further, it may be any of a PVA (Patterned Vertical Alignment) type, a photo-Alignment type (Optical Alignment) and a PSA (Polymer-stabilized Alignment) type. The details of these modes are described in detail in Japanese patent laid-open Nos. 2006-215326 and 2008-538819.

In the IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in plane by applying an electric field parallel to the substrate surface. In the IPS mode, black display is performed in a state where no electric field is applied, and absorption axes of the upper and lower pair of polarizing plates are orthogonal to each other. Methods of reducing light leakage in black display in an oblique direction and improving a viewing angle using an optical compensation sheet are disclosed in japanese patent application laid-open nos. 10-054982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[ organic EL display device ]

As an example of the image display device of the present invention, an organic EL display device is preferably provided with the polarizing plate, the plate having a λ/4 function (hereinafter, also referred to as "λ/4 plate"), and the organic EL display panel of the present invention in this order from the viewing side.

Here, the "plate having a λ/4 function" refers to a plate having a function of converting linearly polarized light of a certain specific wavelength into circularly polarized light (or converting circularly polarized light into linearly polarized light), and examples of a mode in which the λ/4 plate has a single-layer structure include a stretched polymer film and a retardation film in which an optically anisotropic film having a λ/4 function is provided on a support, and a mode in which the λ/4 plate has a multilayer structure include a broadband λ/4 plate in which a λ/4 plate and a λ/2 plate are laminated.

The organic EL display panel is a display panel including organic EL elements in which an organic light-emitting layer (organic electroluminescent layer) is interposed between electrodes (between a cathode and an anode). The structure of the organic EL display panel is not particularly limited, and a known structure can be adopted.

Examples

The present invention will be described in further detail below based on examples. The materials, amounts, ratios, processing contents, processing procedures and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed restrictively by the examples shown below.

[ example 1]

< production of polarizer 1 with photo-alignment film 1 >

The surface of the support of cellulose triacetate film TD80UL (manufactured by Fujifilm Corporation) was subjected to alkali saponification treatment. Specifically, the support was immersed in a 1.5-equivalent aqueous solution of sodium hydroxide at 55 ℃ for 2 minutes, then washed in a water bath at room temperature, and neutralized with 0.1-equivalent sulfuric acid at 30 ℃. After neutralization, the mixture was washed in a water bath at room temperature, and further dried with warm air at 100 ℃.

Subsequently, a roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in an iodine aqueous solution in the MD (Machine Direction) Direction, and dried to obtain a polarizer (polarizing film) having a thickness of 20 μm.

Next, as a polarizer protective film, the alkali-saponified cellulose triacetate film TD80UL was bonded to one surface of the polarizer.

Then, coating liquid 1 for a photo-alignment film having the same composition as the liquid crystal aligning agent (S-3) described in example 3 of jp 2012-155308 a was prepared and coated on the other surface of the polarizer by a wire rod. The polarizer 1 with the photo-alignment film 1 was prepared by drying with warm air at 60 ℃ for 60 seconds.

< production of polarizing plate 1 >

A positive A plate A-1-forming coating liquid A-1 having the following composition was prepared.

In the following formulae L-1 and L-2, the group adjacent to the acryloyloxy group represents an allyl group (a group in which a methyl group is substituted with a vinyl group), and the polymerizable liquid crystal compounds L-1 and L-2 represent a mixture of positional isomers having different methyl positions.

[ chemical formula 6]

The prepared polarizer 1 with the photo-alignment film 1 was irradiated with ultraviolet rays using an ultra-high pressure mercury lamp under the atmosphere. At this time, a wire grid polarizer (ProFlux PPL02, manufactured by Moxtek) was exposed in parallel to the surface of the photo-alignment film 1, and photo-alignment treatment was performed. The illuminance of the ultraviolet light used at this time is set in the UV-A region (ultraviolet A wave, integrated wavelength of 380nm to 320 nm)10mJ/cm²。

Subsequently, the coating liquid A-1 for forming the positive A plate A-1 was applied to the photo-alignment treated surface by using a bar coater. After heating and aging at a film surface temperature of 100 ℃ for 20 seconds and cooling to 55 ℃, 300mJ/cm was irradiated under air using an air-cooled metal halide lamp (EYE GRAPHICS Co., Ltd.; manufactured by Ltd.)²The orientation state of the ultraviolet rays (2) is fixed, thereby forming the polarizing plate 1. That is, the obtained polarizing plate 1 is provided with a positive a plate a-1 as an optically anisotropic film (retardation film), a photo-alignment film 1, a polarizer 1, and a polarizer protective film in this order.

In the positive a plate a-1 formed, the slow axis direction was perpendicular to the absorption axis of the polarizing plate (i.e., the polymerizable liquid crystal compound was aligned perpendicular to the absorption axis of the polarizing plate). As a result of measuring the dependence of Re on the incident light angle and the tilt angle of the optical axis of Re using Axo Scan OPMF-1 (manufactured by Opto Science, Inc.) for the positive A plate A-1, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly (horizontally) aligned at a wavelength of 550 nm.

[ example 2]

A polarizing plate 2 of example 2 was produced in the same manner as in example 1 except that the loading of the specific acidic compound a-1 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 2 is referred to as "positive a plate a-2".

As a result of measurement of the optical characteristics of the positive A plate A-2, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 3]

A polarizing plate 3 of example 3 was produced in the same manner as in example 1, except that 0.50 parts by mass of the specific acidic compound a-2 represented by the following formula a-2 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 3 is referred to as "positive a plate a-3".

As a result of measurement of the optical characteristics of the positive A plate A-3, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 7]

[ example 4]

A polarizing plate 4 of example 4 was produced in the same manner as in example 3 except that the loading of the specific acidic compound a-2 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 4 is referred to as "positive a plate a-4".

As a result of measurement of the optical characteristics of the positive A plate A-4, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 5]

A polarizing plate 5 of example 5 was produced in the same manner as in example 1, except that 0.50 parts by mass of the specific acidic compound a-3 represented by the following formula a-3 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 5 is referred to as "positive a plate a-5".

As a result of measurement of the optical characteristics of the positive A plate A-5, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 8]

[ example 6]

A polarizing plate 6 of example 6 was produced in the same manner as in example 5 except that the loading of the specific acidic compound a-3 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 6 is referred to as "positive a plate a-6".

As a result of measurement of the optical characteristics of the positive A plate A-6, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 7]

A polarizing plate 7 of example 7 was produced in the same manner as in example 1, except that 0.50 part by mass of the specific acidic compound a-4 represented by the following formula a-4 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 7 is referred to as "positive a plate a-7".

As a result of measurement of the optical characteristics of the positive A plate A-7, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 9]

[ example 8]

A polarizing plate 8 of example 8 was produced in the same manner as in example 7 except that the loading of the specific acidic compound a-4 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 8 is referred to as "positive a plate a-8".

As a result of measurement of the optical characteristics of the positive A plate A-8, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 9]

A polarizing plate 9 of example 9 was produced in the same manner as in example 1 except that 0.50 parts by mass of a specific acidic compound a-5 represented by the following formula a-5 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 9 is referred to as "positive a plate a-9".

As a result of measurement of the optical characteristics of the positive A plate A-9, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 10]

[ example 10]

A polarizing plate 10 of example 10 was produced in the same manner as in example 9 except that the loading of the specific acidic compound a-5 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 10 is referred to as "positive a plate a-10".

As a result of measurement of optical characteristics of the positive A plate A-10, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 11]

A polarizing plate 11 of example 11 was produced in the same manner as in example 9 except that the loading of the specific acidic compound a-5 was changed to 5.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 11 is referred to as "positive a plate a-11".

As a result of measurement of the optical characteristics of the positive A plate A-11, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 12]

A polarizing plate 12 of example 12 was produced in the same manner as in example 1, except that 0.50 part by mass of the specific acidic compound a-6 represented by the following formula a-6 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 12 is referred to as "positive a plate a-12".

As a result of measurement of the optical characteristics of the positive A plate A-12, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 11]

[ example 13]

A polarizing plate 13 of example 13 was produced in the same manner as in example 12 except that the loading of the specific acidic compound a-6 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 13 is referred to as "positive a plate a-13".

As a result of measurement of the optical characteristics of the positive A plate A-13, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 14]

A polarizing plate 14 of example 14 was produced in the same manner as in example 12 except that the loading of the specific acidic compound a-6 was changed to 5.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 14 is referred to as "positive a plate a-14".

As a result of measurement of the optical characteristics of the positive A plate A-14, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 15]

A polarizing plate 15 of example 15 was produced in the same manner as in example 1 except that 0.50 parts by mass of the specific acidic compound a-7 represented by the following formula a-7 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 15 is referred to as "positive a plate a-15".

As a result of measurement of the optical characteristics of the positive A plate A-15, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 12]

[ example 16]

A polarizing plate 16 of example 16 was produced in the same manner as in example 15, except that the loading of the specific acidic compound a-7 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 16 is referred to as "positive a plate a-16".

As a result of measurement of the optical characteristics of the positive A plate A-16, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 17]

A polarizing plate 17 of example 17 was produced in the same manner as in example 1 except that 0.50 parts by mass of the specific acidic compound a-8 represented by the following formula a-8 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 17 is referred to as "positive a plate a-17".

As a result of measurement of the optical characteristics of the positive A plate A-17, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 13]

[ example 18]

A polarizing plate 18 of example 18 was produced in the same manner as in example 17 except that the loading of the specific acidic compound a-8 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 18 is referred to as "positive a plate a-18".

As a result of measurement of the optical characteristics of the positive A plate A-18, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 19]

A polarizing plate 19 of example 19 was produced in the same manner as in example 1, except that 0.50 parts by mass of the specific acidic compound a-9 represented by the following formula a-9 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 19 is referred to as "positive a plate a-19".

As a result of measurement of the optical characteristics of the positive A plate A-19, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 14]

[ example 20]

A polarizing plate 20 of example 20 was produced in the same manner as in example 19 except that the loading of the specific acidic compound a-9 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 20 is referred to as "positive a plate a-20".

As a result of measurement of the optical characteristics of the positive A plate A-20, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 21]

A polarizing plate 21 of example 21 was produced in the same manner as in example 1 except that 0.50 parts by mass of the specific acidic compound a-10 represented by the following formula a-10 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 21 is referred to as "positive a plate a-21".

As a result of measurement of the optical characteristics of the positive A plate A-21, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 15]

[ example 22]

A polarizing plate 22 of example 22 was produced in the same manner as in example 9 except that the loading of the specific acidic compound a-5 was changed to 0.10 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 22 is referred to as "positive a plate a-22".

As a result of measurement of the optical characteristics of the positive A plate A-22, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 23]

A polarizing plate 23 of example 23 was produced in the same manner as in example 7 except that the loading of the specific acidic compound a-4 was changed to 12.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 23 is referred to as "positive a plate a-23".

As a result of measurement of the optical characteristics of the positive A plate A-23, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 24]

A positive A plate A-24-forming coating liquid A-24 having the following composition was prepared by referring to the description of example 1 of Japanese patent application laid-open No. 2012-021068.

[ chemical formula 16]

A polarizing plate 24 of example 24 was produced in the same manner as in example 1, except that the coating liquid a-24 for forming a positive a plate a-24 was used in place of the coating liquid a-1 for forming a positive a plate a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 24 is referred to as "positive a plate a-24".

As a result of measurement of the optical characteristics of the positive A plate A-22, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.18, Re (650)/Re (550) was 1.02, the tilt angle of the optical axis was 0.4 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 25]

A polarizing plate 25 of example 25 was produced in the same manner as in example 24 except that the loading of the specific acidic compound a-5 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 25 is referred to as "positive a plate a-25".

As a result of measurement of the optical characteristics of the positive A plate A-25, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 26]

A polarizing plate 26 of example 26 was produced in the same manner as in example 24 except that the loading of the specific acidic compound a-5 was changed to 5.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 26 is referred to as "positive a plate a-26".

As a result of measurement of the optical characteristics of the positive A plate A-26, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 27]

A polarizing plate 27 of example 27 was produced in the same manner as in example 24 except that the following polymerizable liquid crystal compound L-7 was used in place of the polymerizable liquid crystal compound L-5. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 27 is referred to as "positive a plate a-27".

As a result of measurement of the optical characteristics of the positive A plate A-27, Re (550)/Re (450) was 1.20, Re (650)/Re (550) was 1.05, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 17]

[ example 28]

A polarizing plate 28 of example 28 was produced in the same manner as in example 27 except that the loading of the specific acidic compound a-5 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 28 is referred to as "positive a plate a-28".

As a result of measurement of optical characteristics of the positive A plate A-28, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 29]

A polarizing plate 29 of example 29 was produced in the same manner as in example 27 except that the loading of the specific acidic compound a-5 was changed to 5.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 29 is referred to as "positive a plate a-29".

As a result of measurement of the optical characteristics of the positive A plate A-29, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 30]

A polarizing plate 30 of example 30 was produced in the same manner as in example 1, except that 2.00 parts by mass of the specific acidic compound a-14 represented by the following formula a-14 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 30 is referred to as "positive a plate a-30".

As a result of measurement of the optical characteristics of the positive A plate A-30, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 18]

[ example 31]

A polarizing plate 31 of example 31 was produced in the same manner as in example 1 except that 0.5 part by mass of a specific acidic compound a-15 represented by the following formula a-15 was used instead of the specific acidic compound a-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 31 is referred to as "positive a plate a-31".

As a result of measurement of the optical characteristics of the positive A plate A-31, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 19]

[ example 32]

A polarizing plate 32 of example 32 was produced in the same manner as in example 31 except that the loading of the specific acidic compound a-15 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 32 is referred to as "positive a plate a-32".

As a result of measurement of optical characteristics of the positive A plate A-32, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 33]

A positive A plate A-33-forming coating liquid A-33 having the following composition was prepared.

[ chemical formula 20]

Subsequently, the coating liquid A-33 for forming the positive A plate A-33 was applied to the photo-alignment treated surface by using a bar coater. After heating and aging at a film surface temperature of 135 ℃ for 20 seconds and cooling to 120 ℃, 1000mJ/cm was irradiated under air using an air-cooled metal halide lamp (EYE GRAPHICS Co., Ltd.; manufactured by Ltd.)²By fixing the orientation state of the ultraviolet rays, thereby forming polarizationAnd a sheet 33. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 33 is referred to as "positive a plate a-33".

As a result of measurement of the optical characteristics of the positive A plate A-33, at a wavelength of 550nm, Re was 140nm, Rth was 73nm, Re (550)/Re (450) was 1.22, Re (650)/Re (550) was 1.03, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ example 34]

A polarizing plate 34 of example 34 was produced in the same manner as in example 33 except that the loading of the specific acidic compound a-15 was changed to 2.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate 34 is referred to as "positive a plate a-34".

As a result of measurement of the optical characteristics of the positive A plate A-34, at a wavelength of 550nm, Re was 140nm, Rth was 73nm, Re (550)/Re (450) was 1.22, Re (650)/Re (550) was 1.03, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

Comparative example 1

A polarizing plate B1 of comparative example 1 was produced in the same manner as in example 1, except that the specific acidic compound a-1 was not used. In the following description, the optically anisotropic film (retardation film) of the polarizing plate B1 is referred to as "positive a plate B-1".

As a result of measurement of the optical characteristics of the positive A plate B-1, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

Comparative example 2

A polarizing plate B2 of comparative example 2 was produced in the same manner as in example 1 except that 0.10 part by mass of an acidic compound B-1 represented by the following formula B-1 was used in place of the specific acidic compound A-1. In the following description, the optically anisotropic film (retardation film) of the polarizing plate B2 is referred to as "positive a plate B-2".

As a result of measurement of the optical characteristics of the positive A plate B-2, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ chemical formula 21]

Comparative example 3

A polarizing plate B3 of comparative example 3 was produced in the same manner as in example 7, except that the loading of the specific acidic compound a-4 was changed to 25.00 parts by mass. In the following description, the optically anisotropic film (retardation film) of the polarizing plate B3 is referred to as "positive a plate B-3".

As a result of measurement of the optical characteristics of the positive A plate B-3, at a wavelength of 550nm, Re was 145nm, Rth was 73nm, Re (550)/Re (450) was 1.12, Re (650)/Re (550) was 1.01, the tilt angle of the optical axis was 0 °, and the polymerizable liquid crystal compound was uniformly aligned.

[ durability ]

The polarizing plates produced in the above examples and comparative examples were obtained by bonding a front a plate to the glass side of a glass plate via an adhesive (trade name "SK 2057", manufactured by Soken Chemical & Engineering co., ltd.).

The durability of the retardation value (Re) at a wavelength of 550nm was evaluated by using Axoscan (OPMF-1, manufactured by Axometrics) according to the following criteria. The results are shown in table 4 below.

In addition, as for the test conditions, a test was performed in which the test piece was left at 105 ℃ for 120 hours.

AA: the change of the Re value after the test relative to the initial Re value is less than 3 percent of the initial value

A: the change of the Re value after the test relative to the initial Re value is more than 3% and less than 6%

B: the variation of the Re value after the test with respect to the initial Re value is 6% or more but less than 12% of the initial value

C: the change of the Re value after the test relative to the initial Re value is more than 12% and less than 20% of the initial value

D: the change of the Re value after the test relative to the initial Re value is more than 20 percent of the initial value

[ Table 4]

The relative terms denote the amount (mass part) to 100 mass parts of the total of the polymerizable liquid crystal compound (1) and the polymerizable compound.

From the results shown in table 4, it was found that: in the case where the specific acidic compound is not blended, the durability of the optically anisotropic film is poor (comparative example 1).

And, found that: when an acidic compound having a pKa outside the range of more than-10 and 5 or less was used, the durability of the optically anisotropic film was poor (comparative example 2).

Moreover, it was found that: even in the case of using a specific acidic compound having a pKa in the range of more than-10 and 5 or less, the durability of the optically anisotropic film was poor when the amount was large (comparative example 3).

In contrast, it was found that: when a specific amount of a specific acidic compound having a pKa in the range of more than-10 and 5 or less is blended in a specific polymerizable liquid crystal compound, the durability of the formed optically anisotropic film is good (examples 1 to 34).

Further, from the comparison of examples 1 to 23 and examples 30 to 32, it was found that: by satisfying the above formula (I) with the specific acidic compound, the durability of the formed optically anisotropic film is more excellent.

Similarly, from the comparison of examples 1 to 23 and examples 30 to 32, it was found that: when the molecular weight of the specific acidic compound is 120 or more, the durability of the formed optically anisotropic film is further improved.

Similarly, from the comparison of examples 1 to 23 and examples 30 to 32, it was found that: when the acid compound is at least 1 compound selected from the group consisting of phosphoric acid compounds, phosphonic acid compounds, and sulfonic acid compounds, the durability of the formed optically anisotropic film tends to be better, and particularly, when the specific acid compound is a phosphonic acid compound or a sulfonic acid compound, the durability of the formed optically anisotropic film tends to be better.

Description of the symbols

10-optical film, 12-optically anisotropic layer, 14-oriented film, 16-support, 18-hard coat layer.

Claims

1. A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound represented by the following formula (1) and an acidic compound,

the acid compound has a pKa of more than-10 and 5 or less,

the content of the acidic compound is 20 parts by mass or less per 100 parts by mass of the polymerizable liquid crystal compound,

wherein, in the formula (1),

ar represents an n-valent aromatic group,

d represents a single bond, -COO-or-OCO-,

a represents an aromatic ring having 6 or more carbon atoms which may have a substituent, or a cycloalkane ring having 6 or more carbon atoms which may have a substituent,

l represents a polymerizable group, and L represents a polymerizable group,

m represents an integer of 0 to 2, n represents an integer of 1 or 2,

wherein D, A, SP and L, which are plural depending on the number of m or n, may be the same as each other or different from each other.

2. The polymerizable liquid crystal composition according to claim 1,

the pKa value of the acidic compound and the content of the acidic compound per 100 parts by mass of the polymerizable liquid crystal compound satisfy the following formula (I),

the content value/(pKa value +10) of 0.01 is less than or equal to 1.5 (I).

3. The polymerizable liquid crystal composition according to claim 1 or 2,

the acidic compound has a molecular weight of 120 or more.

4. The polymerizable liquid crystal composition according to claim 1 or 2,

the acidic compound is at least 1 compound selected from the group consisting of a phosphoric acid compound, a phosphonic acid compound, and a sulfonic acid compound.

5. The polymerizable liquid crystal composition according to claim 1 or 2,

n in the formula (1) represents 2, and Ar in the formula (1) represents an aromatic ring selected from any one of the groups represented by the following formulas (Ar-1) to (Ar-5),

wherein in the formulae (Ar-1) to (Ar-5),

denotes a bonding position with an oxygen atom,

Q¹represents a group of N or CH,

Q²represents-S-, -O-or-N (R)¹)-，R¹Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,

Y¹an optionally substituted aromatic hydrocarbon group having 6 to 12 carbon atoms or an aromatic heterocyclic group having 3 to 12 carbon atoms,

Z¹、Z²and Z³Independently represents a hydrogen atom, a C1-20 aliphatic hydrocarbon group,A C3-20 alicyclic hydrocarbon group having a valence of 1, a C6-20 aromatic hydrocarbon group having a valence of 1, a halogen atom, a cyano group, a nitro group, -OR²、-NR³R⁴or-SR⁵，R²～R⁵Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Z¹And Z²May be bonded to each other to form an aromatic ring,

A¹and A²Each independently represents a group selected from-O-, -N (R)⁶) A radical of the group consisting of-S-and-CO-, R⁶Represents a hydrogen atom or a substituent group,

x represents a non-metal atom of group 14 to 16 to which a hydrogen atom or a substituent may be bonded,

D¹and D²Each independently represents a single bond or-CO-, -O-, -S-, -C (-S) -, -CR⁷R⁸-、-CR⁹＝CR¹⁰-、-NR¹¹-, or a 2-valent linking group consisting of a combination of 2 or more of them, R⁷～R¹¹Each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms,

SP¹and SP²Each independently represents a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or at least 1-CH constituting a linear or branched alkylene group having 1 to 12 carbon atoms₂A linking group having a valence of 2, substituted by-O-, -S-, -NH-, -N (Q) -or-CO-, Q represents a substituent,

L¹and L²Each independently represents an organic group having a valence of 1,

ax represents an organic group having 2 to 30 carbon atoms having at least 1 aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring,

ay represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, or an organic group having 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring,

the aromatic ring of Ax and Ay may have a substituent, Ax and Ay may be bonded to each other to form a ring,

Q³represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.

6. An optically anisotropic film obtained by polymerizing the polymerizable liquid crystal composition according to any one of claims 1 to 5.

7. The optically anisotropic film according to claim 6,

the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition is horizontally aligned after polymerization.

8. An optical film having the optically anisotropic film of claim 6 or 7.

9. A polarizing plate having the optical film of claim 8 and a polarizer.

10. An image display device having the optical film of claim 8 or the polarizing plate of claim 9.